Semiconductor light emitting device

ABSTRACT

Provided are a semiconductor light emitting device and a method for manufacturing the same. The semiconductor light emitting device comprises a first electrode on an region of top surface of a first conductive semiconductor layer; a second electrode layer under a second conductive semiconductor layer; and a conductive support member under the second electrode layer, wherein the second conductive semiconductor layer includes a plurality of recesses on a lower portion of the second conductive semiconductor layer, wherein the second electrode layer has an uneven structure corresponding to the plurality of recesses.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of U.S. patent application Ser. No.12/619,038 filed on Nov. 16, 2009 now U.S. Pat. No. 8,222,656, whichclaims priority under 35 U.S.C. 119 to Korean Patent Application No.10-2008-0114280 (filed on Nov. 17, 2008), which is hereby incorporatedby reference in its entirety.

BACKGROUND

The present disclosure relates to a semiconductor light emitting device.

Group III-V nitride semiconductors are being widely used as the corematerials of light emitting devices such as Light Emitting Diodes (LEDs)and Laser Diodes (LDs) due to their physical and chemicalcharacteristics. The group III-V nitride semiconductors includesemiconductor materials expressed as the chemical formula ofInxAlyGal-x-yN (where 0≦x≦1, 0≦y≦1, and 0≦x+y≦1).

The LED is a sort of semiconductor device that converts electricalsignals into optical signals (e.g., infrared rays or other light) usingthe characteristics of compound semiconductors to use the opticalsignals as transmission/reception signals or light sources.

The LED or LD using nitride semiconductor materials is widely used forlight emitting devices to obtain light. For example, the LED or LD isapplied to various products such as a light emitting portion of keypadsof mobile phones, electronic display boards and lighting devices as alight source.

Embodiments provide a semiconductor light emitting device comprising asecond electrode layer having an unevenness on a light emittingstructure.

Embodiments provide a semiconductor light device comprising adiscontinuous first semiconductor layer and a second electrode layerhaving an unevenness on a compound semiconductor layer.

An embodiment provides a semiconductor light emitting device comprising:a light emitting structure including a first conductive semiconductorlayer, a second conductive semiconductor layer under the firstconductive semiconductor layer, and an active layer between the firstconductive semiconductor layer and the second conductive semiconductorlayer; a first electrode on an region of a top surface of the firstconductive semiconductor layer; a second electrode layer under the lightemitting structure; and a conductive support member under the secondelectrode layer, wherein the second conductive semiconductor layerincludes a plurality of recesses on a lower portion of the secondconductive semiconductor layer, wherein the second electrode layerincludes a plurality of conductive layers having an uneven structurealong the plurality of recesses, wherein a top surface of the conductivesupport member has a width wider that of a top surface of the secondconductive semiconductor layer.

An embodiment provides a semiconductor light emitting device comprising:a light emitting structure including a first conductive semiconductorlayer, a second conductive semiconductor layer under the firstconductive semiconductor layer, and an active layer between the firstconductive semiconductor layer and the second conductive semiconductorlayer; a first electrode on an region of a top surface of the firstconductive semiconductor layer; a second electrode layer under the lightemitting structure; and a conductive support member under the secondelectrode layer, wherein the second conductive semiconductor layerincludes a plurality of recesses on a lower portion of the secondconductive semiconductor layer, wherein the second electrode layerincludes a plurality of metal layers having an uneven structurecorresponding to the plurality of recesses, wherein the top surface ofthe first conductive semiconductor layer has an roughness, wherein a topsurface of the conductive support member has a width wider that of a topsurface of the second conductive semiconductor layer.

An embodiment provides a semiconductor light emitting device comprising:a plurality of compound semiconductor layers comprising a firstconductive type semiconductor layer, an active layer, and a secondconductive type semiconductor layer; a first semiconductor layerdiscontinuously protruding from the second conductive type semiconductorlayer; a first electrode under the first conductive type semiconductorlayer; a light-transmitting channel layer around a circumference of anupper surface of the second conductive type semiconductor layer; asecond electrode layer on the second conductive type semiconductor layerand the first semiconductor layer; and a conductive support member onthe second electrode layer.

The details of one or more embodiments are set forth in the accompanyingdrawings and the description below. Other features will be apparent fromthe description and drawings, and from the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side-sectional view illustrating a semiconductor lightemitting device according to a first embodiment.

FIG. 2 is a view illustrating a protruding structure of a secondconductive type semiconductor layer of FIG. 1.

FIG. 3 is a view illustrating an example of light reflection at aninterface between the second conductive type semiconductor layer and thesecond electrode layer of FIG. 1.

FIGS. 4 through 8 are views illustrating a process for manufacturing asemiconductor light emitting device according to a first embodiment.

FIG. 9 is a side cross-sectional view of a semiconductor light emittingdevice according to a second embodiment.

FIG. 10 is a graph illustrating an optical power with respect to aninjection current in semiconductor light emitting devices according to afirst embodiment and a comparative embodiment.

FIG. 11 is a side cross-sectional view illustrating a light emittingdevice package according to a third embodiment.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Reference will now be made in detail to the embodiments of the presentdisclosure, examples of which are illustrated in the accompanyingdrawings. In description of embodiments, the ‘on’ or ‘under’ of eachlayer may be described with reference to the accompanying drawings, andthe thickness of the each layer will also be described as an example andis not limited to the thickness shown in the accompanying drawings.

In the description of embodiments, it will be understood that when alayer (or film), region, pattern or structure is referred to as being‘on’ or ‘under’ another layer (or film), region, pad or pattern, theterminology of ‘on’ and ‘under’ includes both the meanings of ‘directly’and ‘indirectly’.

FIG. 1 is a side-sectional view illustrating a semiconductor lightemitting device according to a first embodiment. FIG. 2 is a viewillustrating a protruding structure of a second conductive typesemiconductor layer of FIG. 1. FIG. 3 is a view illustrating an exampleof light reflection at an interface between the second conductive typesemiconductor layer and the second electrode layer of FIG. 1.

Referring to FIG. 1, a semiconductor light emitting device 100 includesa first conductive type semiconductor layer 110, an active layer 120, asecond conductive type semiconductor layer 130, a first semiconductorlayer 135, a second electrode layer 150 of an uneven shape, a conductivesupport member 160, and a first electrode 170.

The semiconductor light emitting device 100 includes an LED using aplurality of compound semiconductors, for example, compoundsemiconductors of group III-V elements. The LED may be a colored LED ora UV LED which emits blue light, green light, or red light. Lightemitted by the LED may be diversely implemented within the technicalscope of embodiments.

The plurality of compound semiconductor layers include a firstconductive type semiconductor layer 110, an active layer 120, and asecond conductive type semiconductor layer 130.

The first conductive type semiconductor layer 110 may be selected fromthe compound semiconductors of group III-V elements doped with a firstconductive type dopant, for example, GaN, AlN, AlGaN, InGaN, InN,InAlGaN, AlInN, AlGaAs, GaP, GaAs, GaAsP and AlGaInP. When the firstconductive type semiconductor layer 110 is an N-type semiconductorlayer, the first conductive type dopant may include an N-type dopantsuch as Si, Ge, Sn, Se, Te. The first conductive type semiconductorlayer 110 may be formed as a mono- or a multi-layer, but is not limitedthereto.

A first electrode 170 is formed under the first conductive typesemiconductor layer 110. The first electrode 170 is formed in a certainshape or pattern, but is not limited thereto. A roughness pattern 115may be formed on the undersurface of the first conductive typesemiconductor layer 110.

The active layer 120 is formed on the first conductive typesemiconductor layer 110, and may be formed in a single- or a multiplequantum well structure. The active layer 120 may be formed to have theperiodic lamination of a well layer and a barrier layer, for example, anInGaN well layer/GaN barrier layer, an InGaN well layer/AlGaN barrierlayer, or InGaN well layer/InGaN well layer using the compoundsemiconductor materials of group III-V elements. A conductive type cladlayer may be formed on and/or under the active layer 120, and may beformed of a GaN-based semiconductor.

The second conductive type semiconductor layer 130 may be formed on theactive layer 120, and may be selected from the compound semiconductorsof group III-V elements doped with a second conductive type dopant, forexample, GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, AlGaAs, GaP, GaAs,GaAsP and AlGaInP. When the second conductive type semiconductor layer130 is a P-type semiconductor layer, the second conductive type dopantmay include a P-type dopant such as Mg and Zn. The second conductivesemiconductor layer 130 may be formed in a mono- or a multi-layer, butis not limited thereto.

The first conductive type semiconductor layer 110, the active layer 120,and the second conductive type semiconductor layer 130 may be defined asa light emitting structure.

An N-type semiconductor layer or a P-type semiconductor layer may beformed on the second conductive type semiconductor layer 130. The firstconductive type semiconductor layer 110 may be implemented in a P-typesemiconductor layer, and the second conductive type semiconductor layer130 may be implemented in an N-type semiconductor layer. Thus, the lightemitting structure may include at least one of an N-P junction, a P-Njunction, an N-P-N junction, and a P-N-P junction.

The first semiconductor layer 135 is formed on the second conductivetype semiconductor layer 130. The first semiconductor layer 135 may beprotruded from the upper surface of the second conductive typesemiconductor layer 130, and may be formed at a regular or irregularinterval. The first semiconductor layer 135 is formed to have adiscontinuous protrusion, for example, a cone shape or a pyramid shape.

The first semiconductor layer 135 may be formed of the same or differentsemiconductor material from the second conductive type semiconductorlayer 130. The first semiconductor layer 135 may be formed of at leastone of, for example, GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN,AlGaAs, GaP, GaAs, GaAsP, and AlGaInP. The first semiconductor layer 135may be formed of an undoped semiconductor layer, a semiconductor layerdoped with a first conductive type dopant, a semiconductor doped with asecond conductive type dopant.

Referring to FIG. 2, the thickness T of the first semiconductor layer135 may ranges from about 0.1 μm to about 2 μm. The maximum diameter ofthe first semiconductor layer 135 may ranges from about 1.0 μm to about10 μm.

One side surface of the first semiconductor layer 135 may be inclined atan inside angle θ of, for example, about 55 degrees to about 57 degreeswith the respect to the horizontal surface of the second conductive typesemiconductor layer 130. Here, the inside angle θ of the firstsemiconductor layer 135 may vary with the crystal properties of amaterial forming the first semiconductor layer 135. The interval betweenthe protrusions of the first semiconductor layer 135 may range fromabout 100 nm to about 100 μm.

The shape of the first semiconductor layer 135 may be formed in athree-dimensional shape, for example, a cone shape or a pyramid shapewith various base surfaces such as a diamond shape, having an inclinedsidewall, but can be modified within the technical scope of theembodiments. The first semiconductor layer 135 may be formed in atapered shape, the width of the upper part of which is smaller than thatof the lower part.

Here, the first semiconductor layer 135 may be formed at a regular orirregular interval on the second conductive type semiconductor layer 130through a selective growth or etching method.

Referring to FIG. 1, the first semiconductor layer 135 is protruded fromthe surface of the second conductive type semiconductor layer 130 tohave an uneven structure.

A second electrode layer 150 is formed on the second conductive typesemiconductor layer 130 and the first semiconductor layer 135. Theundersurface of the second electrode layer 150 may have an uneven shapecorresponding to the shape of the first semiconductor layer 130.

The uneven shape of the second electrode layer 150 may have the sameangle and shape as the shape of the first semiconductor layer 135. Theprotruding shape of the second electrode layer 150 may be inclined. Thesecond electrode layer 150 may be formed in a cone or inverse-cone shapealong the second conductive type semiconductor layer 130.

The second electrode layer 150 may include at least one of an ohmiccontact layer, a reflection layer, and an adhesive layer. The ohmiccontact layer may include at least one of, for example, indium tin oxide(ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), indiumaluminum zinc oxide (IAZO), indium gallium zinc oxide (IGZO), indiumgallium tin oxide (IGTO), aluminum zinc oxide (AZO) and antimony tinoxide (ATO), gallium zinc oxide (GZO), IrOx, RuOx, RuOx/ITO, Ni/IrOx/Au,Ni/IrOx/Au/ITO, Pt, Ni, Au, Rh and Pd. The reflection layer may includea layer formed of Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au, Hf, or analloy of at least two thereof. The adhesive layer may include at leastone of Ti, Au, Sn, Ni, Cr, Ga, In, Bi, Cu, Ag, and Ta.

The second electrode layer 150 may be used as a seed layer for a platingprocess.

The recess of the second electrode layer 150 is formed on the secondconductive type semiconductor layer 130, and the protrusion of thesecond electrode layer 150 is formed to have a shape corresponding tothe first semiconductor layer 135. At least one of the recess andprotrusion of the second electrode layer 150 may be formed to be aninferior conductive region.

Also, an ohmic contact layer (not shown) may be formed between thesecond electrode layer 150 and the second conductive type semiconductorlayer 130. The ohmic contact layer may be formed to have a layered shapeor a multiple-pattern on the second conductive type semiconductor layer130, but is not limited thereto. The ohmic contact layer may include atleast one of indium tin oxide (ITO), indium zinc oxide (IZO), indiumzinc tin oxide (IZTO), indium aluminum zinc oxide (IAZO), indium galliumzinc oxide (IGZO), indium gallium tin oxide (IGTO), aluminum zinc oxide(AZO) and antimony tin oxide (ATO), gallium zinc oxide (GZO), IrOx,RuOx, RuOx/ITO, Ni/IrOx/Au, Ni/IrOx/Au/ITO, Ni/IrOx/Au, andNi/IrOx/Au/ITO, but embodiments are not limited thereto. A nonconductorlayer, for example, an MgN layer may be formed between the secondelectrode layer 150 and the second conductive type semiconductor layer130. The nonconductor layer may be disposed between the discontinuousfirst semiconductor layers 135.

The first semiconductor layer 135 may be formed of a semiconductor ofthe same or different polarity from the second conductive typesemiconductor layer 130. The first semiconductor layer 130 may be formedof an undoped semiconductor, a semiconductor doped with a firstconductive type dopant, or a semiconductor doped with a secondconductive type dopant.

When the first semiconductor layer 135 is formed of an undopedsemiconductor or a first conductive type semiconductor, a currentapplied to the second electrode layer 150 may be supplied to the secondconductive type semiconductor layer 130 disposed between the firstsemiconductor layers 135.

When a nonconductor layer is disposed between the first semiconductorlayers 135, the current applied to the second electrode layer may besupplied to the second conductive type semiconductor layer 130 throughthe first semiconductor layer 135.

When the first semiconductor layer 135 is a second conductive typesemiconductor, the current applied to the second electrode layer 150 maybe supplied to the first semiconductor layer 135 and the secondconductive type semiconductor layer 130.

A conductive support member 160 may be formed on the second electrodelayer 150, and may serve as a base substrate. The conductive supportmember 160 may be implemented using Cu, Au, Ni, Mo, Cu—W, and carrierwafer such as Si, Ge, GaAs, ZnO, SiC, SiGe, and GaN. The conductivesupport member 160 may be formed by an electroplating method, or may beformed in a sheep shape, but is not limited thereto.

The lower part of the conductive support member 160 may be formed tohave a structure corresponding to the unevenness of the second electrodelayer 150. The thickness of the conductive support member 160 may rangefrom about 30 μm to about 150 μm, but embodiments are not limitedthereto. The second electrode layer 150 and the conductive supportmember 160 may be formed as a reflection electrode layer, for example, asecond electrode unit, but is not limited thereto.

The semiconductor light emitting device 100 is supplied with powerthrough the first electrode 170 and the conductive support member 160,light is emitted from the active layer 120 in all directions.

A portion of the light emitted from the active layer 120 travels to thesecond electrode layer 150. The second electrode layer 150 may changethe critical angle of the incident light using the unevenness structure,thereby improving the external quantum efficiency.

Referring to FIGS. 1 and 3, the light emitting to the second electrodelayer 150 is reflected by the change of the critical angle. The secondelectrode layer 150 changes the reflection angle of the incident light.In this case, the second electrode layer 150 may change the reflectionangle of light smaller than the critical angle that allows the emissionof light, thereby increasing a possibility that light is extracted tothe outside.

Embodiments can improve the external quantum efficiency using adiscontinuous first semiconductor layer 135 and a second electrode layer150 having an uneven shape on a plurality of compound semiconductorlayers or a light emitting structure.

FIGS. 4 through 8 are views illustrating a process for manufacturing asemiconductor light emitting device according to a first embodiment.

Referring to FIG. 4, a substrate 101 is loaded into a growth system, anda compound semiconductor layer of group II to VI elements may be grownthereon.

The examples of the growth systems may include electron beam evaporator,Physical Vapor Deposition (PVD), Chemical Vapor Deposition (CVD), PlasmaLaser Deposition (PLD), dual-type thermal evaporator, sputtering andMetal Organic Chemical Vapor Deposition (MOCVD), but embodiments are notlimited to these systems.

The substrate 101 may be selected from the group consisting of sapphiresubstrate (Al2O3), GaN, SiC, ZnO, Si, GaP, InP, Ga₂O₃, a conductivesubstrate, and GaAs. An unevenness pattern may be formed over thesurface of the substrate 101. At least one layer or pattern, forexample, a ZnO layer (not shown), a buffer layer (not shown), or anundoped semiconductor layer (not shown), which is formed of compoundsemiconductors of group II to VI elements, may be formed over thesubstrate 101.

The buffer layer and the undoped semiconductor layer may be formed usingcompound semiconductors of group III-V elements. The buffer layer mayreduce a difference in lattice constant from the substrate 101. Theundoped semiconductor layer may be formed of an undoped GaN-basedsemiconductor.

A light emitting structure including a plurality of compoundsemiconductor layers is formed on the substrate 101. The light emittingstructure includes a first conductive type semiconductor layer 110, anactive layer 120 on the first conductive semiconductor layer 110, and asecond conductive type semiconductor layer 130 on the active layer 120.

The first conductive type semiconductor layer 110 may be selected fromthe compound semiconductors of group III-V elements doped with a firstconductive type dopant, for example, GaN, AlN, AlGaN, InGaN, InN,InAlGaN, AlInN, AlGaAs, GaP, GaAs, GaAsP and AlGaInP. When the firstconductive type semiconductor 110 is an N-type semiconductor layer, thefirst conductive type dopant includes an N-type dopant such as Si, Ge,Sn, Se and Te. The first conductive type semiconductor layer 110 may beformed as a mono- or multi-layer, but is not limited thereto.

The active layer 120 is formed on the first conductive typesemiconductor layer 110, and may be formed in a single- or a multiplequantum well structure. The active layer 120 may be formed to have theperiodic lamination of a well layer and a barrier layer, for example, anInGaN well layer/GaN barrier layer, an InGaN well layer/AlGaN barrierlayer, or InGaN well layer/InGaN barrier layer using the compoundsemiconductor materials of group III-V elements.

A conductive type clad layer may be formed on and/or under the activelayer 120, and may be formed of a GaN-based semiconductor.

The second conductive semiconductor layer 130 is formed on the activelayer 120, and may be selected from the compound semiconductors of groupIII-V elements doped with a second conductive type dopant, for example,GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN, AlGaAs, GaP, GaAs, GaAsPand AlGaInP. When the second conductive type semiconductor layer 130 isa P-type semiconductor layer, the second conductive type dopant mayinclude a P-type dopant such as Mg and Zn. The second conductive typesemiconductor layer 130 may be formed as a mono- or multi-layer, but isnot limited thereto.

The second conductive type semiconductor layer 130 may include a P-typeGaN layer that is formed to have a certain thickness by supplying a gasincluding P-type dopant such as NH₃, TMGa (or TEGa), and Mg(CP₂Mg).

The first conductive type semiconductor layer 110, the active layer 120,and the second conductive type semiconductor layer 130 may be defined asa light emitting structure. A third conductive type semiconductor layer,for example, an N-type semiconductor layer or a P-type semiconductorlayer may be formed on the second conductive type semiconductor layer130. Thus, the light emitting structure may include at least one of anN-P junction, a P-N junction, an N-P-N junction, and a P-N-P junction.

Referring to FIGS. 4 and 5, the second conductive type semiconductorlayer 130 is grown with a certain thickness. A mask pattern 132 isformed on the second conductive type semiconductor layer 130. Aplurality of opening regions 134 may be formed at a regular or irregularinterval on the mask pattern 132. The opening region 134 of the maskpattern 132 may have a diameter ranging from about 1.0 μm to about 10μm. The interval between the opening regions 134 of the mask pattern 132may range from about 100 nm to about 100 μm.

The second conductive type semiconductor layer 130 is re-grown. Forexample, a P-type GaN layer may be formed to have a certain thickness bysupplying a gas including P-type dopant such as NH₃, TMGa (or TEGa), andMg(CP₂Mg). In this case, the growth temperature and pressure may beadjusted to form the P-type layer. Thus, a first semiconductor layer 135is formed using the opening region 134 of the mask pattern 132. Thefirst semiconductor layer 135 may be formed to have a three-dimensionalshape, which has a vertical section of a triangular shape or a polygonalshape (e.g., trapezoid) and a base plane of a circular or polygonal(e.g., hexagonal) shape. Also, the inclination of the firstsemiconductor layer 135 may have an inside angle θ ranging from about 55degrees to about 57 degrees with respect to the upper surface of thesecond conductive type semiconductor layer 130 as shown in FIG. 2.

If the first semiconductor layer 135 is formed on the second conductivetype semiconductor layer 130, the mask pattern 132 may be removed.

Here, methods for forming the first semiconductor layer 135 will bedescribed as follows. There are two exemplary methods for forming thefirst semiconductor layer 135. In a first method, after the secondconductive type semiconductor layer 130 may be grown to a certainthickness, a dry and/or wet etching may be performed using a maskpattern to form the first semiconductor layer 135 as described above.Here, the first semiconductor layer 135 may be formed of the samematerial as the second conductive type semiconductor layer 130, but isnot limited thereto.

In a second method, a nonconductor layer having an opening region may beformed on the second conductive type semiconductor layer 130. Thenonconductor layer may be implemented using an MgN layer, but is notlimited thereto. The first semiconductor layer 135 may be formed usingthe opening region of the nonconductor layer. Here, the MgN layer may beformed using Mg and ammonia (NH₃). The MgN layer may be formed to havean irregular pattern. Thus, the first semiconductor layer 135 may beformed at an irregular interval on the second conductive typesemiconductor layer 130. Thereafter, the MgN layer may or may not beremoved. Since the MgN layer is a nonconductor, a current applied to thesecond electrode layer may be supplied to the second conductive typesemiconductor layer 130 through the first semiconductor layer 135.

Consequently, the first semiconductor layer 135 may be formed to have anuneven shape on the second conductive type semiconductor layer 130.

The first semiconductor layer 135 may be formed of the same or differentsemiconductor material from the second conductive type semiconductorlayer 130. The first semiconductor layer 135 may be formed of at leastone of, for example, GaN, AlN, AlGaN, InGaN, InN, InAlGaN, AlInN,AlGaAs, GaP, GaAs, GaAsP, and AlGaInP. The first semiconductor layer 135may be formed of a semiconductor of the same or different polarity fromthe second conductive type semiconductor layer 130. The firstsemiconductor layer 135 may be formed of an undoped semiconductor layer,a semiconductor layer doped with a first conductive type dopant, asemiconductor doped with a second conductive type dopant.

Referring to FIG. 6, a second electrode layer 150 is formed on thesecond conductive type semiconductor layer 130. The second electrodelayer 150 may be formed in an inside region or on the entire surface ofthe second conductive type semiconductor layer 130, but is not limitedthereto.

The second electrode layer 150 may include at least one of an ohmiccontact layer, a reflection layer, and an adhesive layer. The ohmiccontact layer may include at least one of, for example, indium tin oxide(ITO), indium zinc oxide (IZO), indium zinc tin oxide (IZTO), indiumaluminum zinc oxide (IAZO), indium gallium zinc oxide (IGZO), indiumgallium tin oxide (IGTO), aluminum zinc oxide (AZO) and antimony tinoxide (ATO), gallium zinc oxide (GZO), IrOx, RuOx, RuOx/ITO, Ni/IrOx/Au,Ni/IrOx/Au/ITO, Pt, Ni, Au, Rh and Pd. The reflection layer may includea layer formed of Ag, Ni, Al, Rh, Pd, Ir, Ru, Mg, Zn, Pt, Au, Hf, or analloy of at least two thereof. The adhesive layer may include at leastone of Ti, Au, Sn, Ni, Cr, Ga, In, Bi, Cu, Ag, and Ta.

The second electrode layer 150 may include a seed layer. The seed layermay include at least one of Ti, Cr, Ta, Cr/Au, Cr/Cu, Ti/Au, Ta/Cu, andTa/Ti/Cu.

The second electrode layer 150 may formed to have an uneven shape alongthe shape of the first semiconductor layer 135 of the second conductivetype semiconductor layer 130. The recess of the second electrode layer150 may have an inverse cone shape, and the protrusion thereof may havea cone shape.

Here, the recess of the second electrode layer 150 may contact thesecond conductive type semiconductor layer 130, and the protrusionthereof may contact the first semiconductor layer 135.

When the first semiconductor layer 135 is an undoped semiconductor or afirst conductive type semiconductor, a current applied to the secondelectrode layer 150 may be supplied to the second conductive typesemiconductor layer 130 disposed between the first semiconductor layers135.

When a nonconductor layer is disposed between the first semiconductorlayers 135, the current applied to the second electrode layer may besupplied to the second conductive type semiconductor layer 130 throughthe first semiconductor layer 135.

When the first semiconductor layer 135 is a second conductive typesemiconductor, the current applied to the second electrode layer 150 maybe supplied through the first semiconductor layer 135 and the secondconductive type semiconductor layer 130.

Also, an ohmic contact layer (not shown) may be formed between thesecond electrode layer 150 and the second conductive type semiconductorlayer 130. The ohmic contact layer may be formed with a layered shape ormultiple-pattern before the second electrode layer 150 is formed. Theohmic contact layer may include at least one of indium tin oxide (ITO),indium zinc oxide (IZO), indium zinc tin oxide (IZTO), indium aluminumzinc oxide (IAZO), indium gallium zinc oxide (IGZO), indium gallium tinoxide (IGTO), aluminum zinc oxide (AZO) and antimony tin oxide (ATO),gallium zinc oxide (GZO), IrOx, RuOx, RuOx/ITO, Ni/IrOx/Au,Ni/IrOx/Au/ITO, Ni/IrOx/Au, and Ni/IrOx/Au/ITO.

Referring to FIG. 7, a conductive support member 160 may be formed onthe second electrode layer 150, and may serve as a base substrate. Theconductive support member 160 may be implemented using Cu, Au, Ni, Mo,Cu—W, and carrier wafer such as Si, Ge, GaAs, ZnO, SiC, SiGe, and GaN.

The conductive support member 160 may be formed by an electroplatingmethod, or may be formed in a sheep shape, but is not limited thereto.The thickness of the conductive support member 160 may range from about30 μm to about 150 μm, but embodiments are not limited thereto.

The lower part of the conductive support member 160 may be formed tohave an evenness matching the unevenness of the second electrode layer150.

Referring to FIGS. 7 and 8, the conductive support member 160 may bepositioned at the base after the conductive support member 160 isformed. Then, the substrate 101 may be removed through a physical and/orchemical removal method.

Through the physical removal method, the substrate 101 may be separatedby a Laser Lift Off (LLO) of irradiating a laser having a wavelength ofa certain range on the substrate. In the chemical removal method, whenanother semiconductor layer (e.g., buffer layer) is interposed betweenthe substrate 101 and the first conductive type semiconductor layer 110,the substrate 101 may be separated by using a wet etchant to remove thebuffer layer.

An etching process such as Inductively Coupled Plasma/Reactive IonEtching (ICP/RIE) or a grinding process may be performed on the surfaceof the first conductive type semiconductor layer 110 after the substrate101 is removed.

The unevenness of the first semiconductor layer 135 of the secondconductive type semiconductor layer 130 and the second electrode layer140 may reinforce an adhesive strength between the compoundsemiconductor layer (e.g., 130) and the second electrode layer 140.Accordingly, even when a laser of the LLO method is irradiated, apeeling between the compound semiconductor layer 130 and the secondelectrode layer 140 can be overcome.

A roughness pattern 115 may be formed on the undersurface of the firstconductive type semiconductor layer 110 through a wet and/or dry etchingmethod.

Then, after a mesa etching is performed on a boundary region betweenchips (i.e., channel region), the semiconductor light emitting device100 may be separated into unit chips. A first electrode 170 having acertain pattern may be formed under the first conductive typesemiconductor layer 110. Here, a process for forming the first electrode170 may be performed before or after the mesa etching, or after theseparation of the semiconductor light emitting device 100, but is notlimited thereto. The first conductive type semiconductor layer 110, theactive layer 120, and the second conductive type semiconductor layer 130may be formed to have outer edges 103 thereof partially cut away.However, the mesa etching is merely a process for separation betweenchips, and embodiments are not limited thereto.

If a forward current is applied to the semiconductor light emittingdevice 100 through the first electrode 170 and the conductive supportmember 160, light is emitted from the active layer 120 in alldirections. In this case, the light incident to the first semiconductorlayer 135 and the second electrode layer 150 of the second conductivetype semiconductor layer 130 may be reflected by a change of thecritical angle. That is, the reflection angle of the light incident tothe second electrode layer 150 of the unevenness structure may bechanged to be reflected. The second electrode layer 150 can reflectlight having a reflection angle smaller than the critical angle thatallows the emission of light. In this case, the light can be reflectedat a greater angle than the critical angle, thereby improving the lightextraction efficiency.

FIG. 9 is a side cross-sectional view of a semiconductor light emittingdevice according to a second embodiment. In the description of thesecond embodiment, detailed descriptions of identical parts to those ofthe first embodiment will be substituted with those of the firstembodiment and be omitted herein.

Referring to FIG. 8, a semiconductor light emitting device 100A includesa light-transmitting channel layer 140 surrounding the circumference ofthe upper surface of the second conductive type semiconductor layer 130.

The channel layer 140 may be formed to have a ring, strip, or flameshape of a continuous or discontinuous pattern along the circumferenceof the second conductive type semiconductor layer 130. That is, thechannel layer 140 may be formed with an open loop shape or closed loopshape. At least a portion of the channel layer 140 may be exposed to achannel region of a light emitting structure, and may be formed toprotect the outer wall of the light emitting structure from humidity orshort-circuit.

The channel layer 140 may be formed to have a certain width along thecircumference of the second conductive type semiconductor layer 130. Theinner side of the channel layer 140 is disposed between the secondelectrode layer 150 and the second conductive type semiconductor layer130, and the outer side of the channel layer 140 is disposed under thesecond electrode layer 150. In this case, the outer side of the channellayer 140 is exposed to the channel region 103 of the compoundsemiconductor layer 110, 120 and 130.

The channel layer 140 may be formed of a light-transmitting insulatingmaterial or light-transmitting conductive material, and may include atleast one of, for example, SiO2, SiO_(x), SiO_(x)N_(y), Si₃N₄, Al₂O₃,TiO₂, ITO (indium tin oxide), IZO (indium zinc oxide), IZTO (indium zinctin oxide), IAZO (indium aluminum zinc oxide), IGZO (indium gallium zincoxide), IGTO (indium gallium tin oxide), AZO (aluminum zinc oxide), ATO(antimony tin oxide), GZO (gallium zinc oxide), IrOx, RuOx, RuOx/ITO,Ni/IrOx/Au, and Ni/IrOx/Au/ITO. Besides the above materials, the channellayer 140 may use a light-transmitting material or a material that israrely fragmented by a laser light, but embodiments are not limitedthereto.

The channel layer 140 may allow the conductive support member 160 to bespaced from the second conductive type semiconductor layer 130. Thechannel layer 140 may minimize metal material fragments generated by alaser beam during a manufacturing process of a semiconductor.

FIG. 10 is a graph illustrating an optical power with respect to aninjection current in semiconductor light emitting devices according toan embodiment and a comparative embodiment.

Referring to FIG. 10, when an injection current of a semiconductor lightemitting device is increased, an output power of an embodiment E2 isincreased by a certain gap G compared to a comparative embodiment E1.Here, the comparative embodiment E1 represents a case where a firstsemiconductor layer and a second electrode layer on a second conductivetype semiconductor layer are flat.

FIG. 11 is a side cross-sectional view illustrating a light emittingdevice package according to a third embodiment.

Referring to FIG. 11, the light emitting package includes a body part20, first and second lead electrode 31 and 32 in the body part 20, alight emitting device 100 to which the first and second lead electrodes31 and 32 are electrically connected, and a molding member 40surrounding the light emitting device 100.

The body part 20 may be formed of silicon, compound resin, or metal, andmay have an inclined surface around the light emitting device 100.

The first and second lead electrodes 31 and 32 are electrically isolatedfrom each other, and provide power to the light emitting device 100.Also, the first and second lead electrodes 31 and 32 may reflect lightgenerated in the light emitting device 100, thereby increasing opticalefficiency. The first and second lead electrodes 31 and 32 also serve toexhaust heat generated in the light emitting device 100 to the outside.

The light emitting device 100 may be disposed on the body part 20 or thefirst and second lead electrodes 31 and 32.

The light emitting device 100 may be electrically connected to the firstlead electrode 31 through a wire, and may be electrically connected tothe lead electrode 32 through a die bonding.

The molding member 40 surrounds the light emitting device 100 to protectthe light emitting device 100. Also, the molding member 40 may include aphosphor to change the wavelength of light emitted from the lightemitting device 100.

After the semiconductor light emitting device according to theembodiment(s) is die-bonded to the second lead electrode 32 through aninsulating substrate or a growth substrate, which is packaged to be usedas a light source of indicating devices, lighting device, and displayingdevices.

In still further another embodiment, a method for manufacturing asemiconductor light emitting device comprises: forming a plurality ofcompound semiconductor layers comprising a first conductive typesemiconductor layer, an active layer, and a second conductive typesemiconductor layer; forming a first semiconductor layer discontinuouslyprotruding from the second conductive type semiconductor layer; forminga second electrode layer a second electrode layer on the secondconductive type semiconductor layer and the first semiconductor layer;forming a conductive support member on the second electrode layer; andforming a first electrode under the first conductive type semiconductorlayer.

Features, structures, and effects described in the above embodiments areincorporated into at least one embodiment of the present invention, butare not limited to only one embodiment. Moreover, features, structures,and effects exemplified in one embodiment can easily be combined andmodified for another embodiment by those skilled in the art. Therefore,these combinations and modifications should be construed as fallingwithin the scope of the present invention.

A semiconductor light emitting device or a light emitting device packageaccording to an embodiment can be used as light sources of displayingdevice, indicating devices, and lighting devices, but is not limitedthereto.

Embodiments can provide a semiconductor light emitting device such as anLED.

Embodiments can improve electrical reliability of a semiconductor lightemitting device.

Embodiments can improve optical efficiency of a vertical-typesemiconductor light emitting device.

Embodiments can apply light source packaged with a semiconductor lightemitting device to lighting devices, indicating devices, and displayingdevices.

Embodiments can improve external quantum efficiency.

Embodiments can enhance an adhesive strength between a semiconductorlayer and a second electrode layer.

Embodiments can improve reliability of a semiconductor light emittingdevice.

Although embodiments have been described with reference to a number ofillustrative embodiments thereof, it should be understood that numerousother modifications and embodiments can be devised by those skilled inthe art that will fall within the spirit and scope of the principles ofthis disclosure. More particularly, various variations and modificationsare possible in the component parts and/or arrangements of the subjectcombination arrangement within the scope of the disclosure, the drawingsand the appended claims. In addition to variations and modifications inthe component parts and/or arrangements, alternative uses will also beapparent to those skilled in the art.

What is claimed is:
 1. A semiconductor light emitting device,comprising: a light emitting structure including a first conductivesemiconductor layer, a second conductive semiconductor layer under thefirst conductive semiconductor layer, and an active layer between thefirst conductive semiconductor layer and the second conductivesemiconductor layer; a first electrode on a region of a top surface ofthe first conductive semiconductor layer; a second electrode layer underthe light emitting structure; a conductive support member under thesecond electrode layer; and a light-transmitting layer including a firstportion disposed under a periphery region of a bottom surface of thesecond conductive semiconductor layer, wherein the second conductivesemiconductor layer includes a plurality of recesses on a lower portionof the second conductive semiconductor layer, wherein the secondelectrode layer includes a plurality of conductive layers having anuneven structure along the plurality of recesses, wherein a top surfaceof the conductive support member has a width wider that of a top surfaceof the second conductive semiconductor layer, wherein thelight-transmitting layer includes a second portion extended outwardlyfrom the bottom surface of the second conductive semiconductor layer,wherein the second electrode layer includes an outer portion extendedoutwardly from the bottom surface of the second conductive semiconductorlayer, and wherein the outer portion of the second electrode layer isdisposed under the second portion of the light-transmitting layer. 2.The semiconductor light emitting device according to claim 1, whereinthe second conductive semiconductor layer includes a plurality ofcontact regions spaced apart from each other between the plurality ofrecesses and the plurality of contact regions are contacted with thesecond electrode layer.
 3. The semiconductor light emitting deviceaccording to claim 1, wherein the plurality of contact regions arephysically contacted with different regions of the second electrodelayer.
 4. The semiconductor light emitting device according to claim 2,wherein the plurality of contact regions are formed at a regularinterval.
 5. The semiconductor light emitting device according to claim4, wherein each of the plurality of recesses comprises an inclined sidesurface with respect to a bottom surface of the plurality of contactregions of the second conductive semiconductor layer.
 6. Thesemiconductor light emitting device according to claim 2, wherein eachof the plurality of recesses comprises an inclined side surface withrespect to a bottom surface of the second conductive semiconductorlayer.
 7. The semiconductor light emitting device according to claim 5,wherein the inclined side surface has an inclination angle less than 57degrees with respect to a horizontal bottom surface of the secondconductive semiconductor layer.
 8. The semiconductor light emittingdevice according to claim 5, wherein the plurality conductive layersincludes a plurality of metal layers having the uneven structure by theplurality of recesses.
 9. The semiconductor light emitting deviceaccording to claim 8, wherein the plurality of metal layers includes atleast three layers including Ti and Au material.
 10. The semiconductorlight emitting device according to claim 8, wherein at least one of thefirst and second conductive semiconductor layers is formed of aGaAs-based semiconductor, wherein the second electrode layer has a widthwider than that of the top surface of the second conductivesemiconductor layer, and wherein the conductive support member includesGe material having a thickness in a range of 30 μm to 150 μm.
 11. Asemiconductor light emitting device, comprising: a light emittingstructure including a first conductive semiconductor layer, a secondconductive semiconductor layer under the first conductive semiconductorlayer, and an active layer between the first conductive semiconductorlayer and the second conductive semiconductor layer; a first electrodeon a region of a top surface of the first conductive semiconductorlayer; a second electrode layer under the light emitting structure; aconductive support member under the second electrode layer; and alight-transmitting layer including a first portion disposed under aperiphery region of a bottom surface of the second conductivesemiconductor layer, wherein the second conductive semiconductor layerincludes a plurality of recesses on a lower portion of the secondconductive semiconductor layer, wherein the second electrode layerincludes a metal layer having an uneven structure corresponding to theplurality of recesses, wherein the top surface of the first conductivesemiconductor layer has an roughness, wherein a top surface of theconductive support member has a width wider that of a top surface of thesecond conductive semiconductor layer, wherein the light-transmittinglayer includes a second portion extended outwardly from the bottomsurface of the second conductive semiconductor layer, wherein the secondelectrode layer includes an outer portion extended outwardly from thebottom surface of the second conductive semiconductor layer, and whereinthe outer portion of the second electrode layer is disposed under thesecond portion of the light-transmitting layer.
 12. The semiconductorlight emitting device according to claim 11, wherein thelight-transmitting layer includes an insulating material of siliconnitride.
 13. The semiconductor light emitting device according to claim11, wherein at least one of the first and second conductivesemiconductor layers is formed of a GaAs-based semiconductor, andwherein the conductive support member includes Ge material having athickness in a range of 30 μm to 150 μm.
 14. The semiconductor lightemitting device according to claim 13, wherein a top surface of thesecond electrode layer has a width wider than that of a top surface ofthe second conductive semiconductor layer.
 15. The semiconductor lightemitting device according to claim 13, wherein the second conductivesemiconductor layer includes a plurality of contact regions spaced apartfrom each other between the plurality of recesses and the plurality ofcontact regions are contacted with the second electrode layer.
 16. Thesemiconductor light emitting device according to claim 15, wherein theplurality of contact regions are physically contacted with differentregions of the second electrode layer, and wherein each of the pluralityof recesses comprises an inclined side surface with respect to thesecond conductive semiconductor layer.
 17. A semiconductor lightemitting device, comprising: a light emitting structure including afirst conductive semiconductor layer, a second conductive semiconductorlayer under the first conductive semiconductor layer, and an activelayer between the first conductive semiconductor layer and the secondconductive semiconductor layer; a first electrode on a region of a topsurface of the first conductive semiconductor layer; a second electrodelayer under the light emitting structure; a conductive support memberunder the second electrode layer; and a light-transmitting layerincluding a first portion disposed under a periphery region of a bottomsurface of the second conductive semiconductor layer, wherein a lowerportion of the light emitting structure includes a plurality ofrecesses, wherein a top surface of the second electrode layer has awidth wider than that of a top surface of the second conductivesemiconductor layer, wherein a top surface of the conductive supportmember has a width wider than that of a top surface of the secondconductive semiconductor layer, wherein the light-transmitting layerincludes a second portion extended outwardly from the bottom surface ofthe second conductive semiconductor layer, wherein the second electrodelayer includes an inner portion formed in an uneven layer structurecorresponding to the plurality of recesses and an outer portion formedin a flat layer structure under the light-transmitting layer, andwherein the flat layer structure is extended outwardly from the unevenlayer structure.
 18. The semiconductor light emitting device accordingto claim 17, wherein a bottom surface of the uneven layer structurecorresponds to the plurality of recesses.
 19. The semiconductor lightemitting device according to claim 18, wherein the second electrodelayer includes a plurality of conductive layers, and wherein the innerportion of the second electrode layer includes a plurality of protrusionregions contacted with the second semiconductor layer.